The long-range goal of these investigations is to elucidate the function(s) of carnitine octanoyltransferase of microsomes (endoplasmic reticulum), mitochondria and peroxisomes as well as the function(s) of microsomal and peroxisomal carnitine acetyltransferase in liver and other tissues. Both transferases occur in mitochondria, microsomes, and peroxisomes of rat and pig liver. Both transferases occur in mitochondria, microsomes, and peroxisomes of rat and pig liver. A goal is to purify and characterize mitochondrial carnitine octanoyltransferase. Standard methods as well as affinity chromatography involving coenzyme A and/or carnitine as the bound substrate will be used for purification of the enzymes. The amount and distribution of the transferases in microsomes of different tissues will be determined. Methodology for identification and quantitation of water-soluble and water-insoluble acylcarnitines will be completed and the techniques will be used to identify the acylcarnitines that occur in tissues and then will be used to determine the levels of these metabolites in tissues that are in different metabolic states such as fed and fasted states and alloxan-induced diabetes. The distribution of the various transferases in tissues, their developmental pattern, and the level and changes in levels of acylcarnitines due to creation of specific metabolic states will be used to ascertain the multiorganelle function(s) of the short- and medium-chain transferases.